"Doffing," which is the operation of removing the full bobbins, and aupplying the spindles with another set, is performed by the attendant called a " minder"—always a female--and an assistant child of either sex, denominated a doffer. In an ordinary sized frame, this generally taken 4-5 minutes ; and, as the bobbins are small, and doffing is a frequent operation, especially in spinning low Nos., it is obvious that a considerable amount of time is expended on that pmcess, besides the coat of keeping a set of openatives to perform it. The latter amounts to 4d.-6d. a spindle per annum. In consequence of this, many attempts have been made to devise some method of supereeding manual by mechanical doffing, one of which, invented by Bernhardt, a epinner of Radcliffe, near Manchester, is generally regarded as a practical succesa, though the first coat of ita application has prevented its extensive adoption.
The throstle-frame has always possessed two great merits, those of being continuous in its operation, and of permitting the employcrient of female labour for its superintendence. These principles have led to numerous efforts to overcome its acknowledged defects, with the result that great improvements have been made from time to time. Amongst the earliest of these efforts must be ranked those of the late G. Bodmer, of Manchester. In patents taken out in 1838 and 1842, there are descriptions of a " bastard " spinning frame--a throatle-frame without fliers, and with mule spindles, on which cops were spun like those in the mule. This frame posseased what would now be called the ring and traveller, and, without much doubt, it forms the basis of the modern ring:frame, the origin of which is generally attributed to American inventors.
The throstle-frame, owing to its being available for the employment of female labour, was always the moat popular spinning machine in the United States ; and the experience gained by its extensive use stimulated invention, and led to its comparatively perfect development.
Whether the ring-frame Ivas an English or American conception originally, it is undoubtedly the fact that it is in the latter country that it has been brought to such a degree of perfection as to render it a better machine than the throstle-frame, and also to endanger, for low and medium Nos., the supremacy hitherto enjoyed by the mule. In this country, during the last few years, it bas attracted a great deal of attention, and been extensively adopted.
The ring-frame is a modified throstle, and preserves its chief features. It differs from the latter machine mainly in having the flier replaced by a ring, which is fitted in the traverse rail. From
this it takes its name. This ring is grooved inside and out, or made vvith flanges, and is furnished with a small piece of flat steel wire bent in a form almost like the letter D, with the vertical -line cut through, to permit its passage over the flange of the ring, when it clips into the groove. This is called the traveller. Its office is to constitute a drag upon the yarn, by means of which the latter is wound upon the bobbin. Its size and weight depend upon the counts of yarn required to be spun : coarse yarns demand the largest rings and heaviest travellers; and the finer yarns, the opposite. The capability of the frame extends from the lowest numbers to 50's or 60's ; but it has not been found expedient as a rule to pass the first-named point.
Owing to the high speed of the spindle-5000-9000 rev. a minute--that has been attained in the ring-frame, it has been found that the dimensions and construction of the spindle are points of vital ,importance. The frame alluded to above is furnished with what is known as the Rabbeth spindle. Of the three illustrations contained in Fig. 549, A represents a section of the spindle complete with bobbin ; B, the spindle with its sleeve ; 0, spindle complete with bobbin. A brief description will suffice to render its construc tion easily comprehensible. The steel spindle Als furnished with a east-iron sleeve B, which is firmly secured to it. This sleeve at its lower extremity has the wharve cast upon it, for the reception of the driving band. A tubular bolster D is constructed to receive the lower part of the spindle. Literally it is a com pound of bolster and footstep. The top of its tube is furnished with a German silver bush E, of which the dark lines indicate the section.
This, when the spindle has been inserted, forms a cavity below, constituting an oil chamber or reservoir H. This effectually secures the per fect lubrication of the spindle foot, and of its frictional portion in the bush E at the top of the bolster D. The chamber carries sufficient oil to ensure perfect lubrication for several months, and experience demonstrates it to be efficient. The question arises at this point as to whether its lubricating properties may not become impaired or destroyed after being sub mitted for a lengthened period to the attrition of the revolving spindle ; or xvhether some chemical action may not be induced which will essentially change its nature. In con tact with brass in the bolster or footstep, after some time, oil becomes turbid, green, and slightly viscid. If this point has been decided favourably, as we are assured, this arrange ment would appear to be unobjectionable.